Many appliances and devices today use electric motors. Many of the appliances, like kitchen appliances such as soybean milk makers or food mixers, want the electric motor to be smaller, lighter and more powerful so as to reduce the size of the appliance with the same performance or to improve the performance of the appliance without increasing its size.
In some conventional kitchen appliances high voltage direct current (HVDC) motors are used. The HVDC motor has a stator and a rotor. The stator has a round housing with one or more permanent magnets fixed to the inner surface of the housing. The rotor has a rotor core and rotor windings wound about poles of the rotor core. The rotor windings are supplied with HVDC power via a commutator and brushes. In a known HVDC motor, the housing of the motor has an outer diameter of 36 mm, the rotor core has an outer diameter of 22.8 mm, and the ratio of the outer diameter of the rotor core to the outer diameter of the housing is 63.3%. The power output of the motor is typically less than 40 watts.
By round housing we mean that the housing has a round or circular cross section. HVDC is generally used to mean a DC voltage of a level derived from a domestic AC electrical supply. Depending on the method of converting the AC power to DC power, the resulting DC power may be between half to same as the supply voltage. Thus HVDC is taken to mean a DC voltage in the range of 50V to 400V.
The present invention aims to provide a permanent magnet motor having higher power output without increasing its size, which is greatly appreciated by the kitchen appliance manufacturers and their customers.